One of this week’s lead snowmobile feeds is from The Seattle Times — December 7, 2007 — http://seattletimes.nwsource.com/

The story follows the release of the list of snowmobiles approved for use in Yellowstone and Grand Teton National Parks. Forty-one sleds appear on the approved list released by the National Park Service for the 2008 — 2009 winter use in the parks. The list is available from http://www.nps.gov/yell/parkmgmt/current_batlist.htm

Of course, what everyone is interested in, is what snowmobiles are on the list and how did they get there? The Times article is quick to point out that at full throttle over half of the list’s models exceed the parks’ 73-decibel noise limit at full throttle. Why? The rules take into consideration that conditions vary, so allow for a 2-decibel variance. In general, the average 2-stroke has a dBA (sound decibal) rating of 78 decibals.

Noise has been an issue with the snowmobile for decades. This 1971 article suggests that snowmobiles should carry a warning label, like cigarettes and alcohol! http://www.garfield.library.upenn.edu/essays/V1p177y1962-73.pdf

Some state legislatures brought noise laws into effect for snowmobiles in 1972. Wisconsin’s law allowed a level of 82 decibels of sound A pressure at 50 feet for snowmobiles made up to 1970. For snowmobiles after 1975 the level was reduced to 78 for sound A pressure at 50 feet.

Thirty-three years later the average snowmobile is still at that 78 decibel level. But what does that really mean? Well, 60 db is the level of a normal conversation. 200 db of Military Sonar has killed some species of beaked whales. The persistent noise level in the city of Delhi (India) is 80 db and 89 db in Chennai (India). In New York the sound levels reach 106 db on subway platforms — and there are nearly 4 million riders each weekday.

Besides sound, the parks regulate snowmobiles based on air emissions: hydrocarbons and carbon monoxide. The average 2-stroke snowmobile produces 150 hyrdocarbons, while the limit is 15. The average 2-stroke snowmobile is measured at 400 in carbon monoxide emissions, while the limit is 120.

What about other sectors? So far only 12 states have set laws to regulate carbon monoxide emissions in cars: http://www.csmonitor.com/2007/0914/p01s02-usgn.html

The general on-road carbon monoxide vehicle emission standards for 2004 through 2006 produced vehicles were 50 g/kW-hr, with an alternate 130 g/kW-hr for severe duty engines. http://www.complianceregs.com/40cfr/ChapterI/subU/Part1048/1048-101.html

Who is planning to regulate the buses (severe duty), RVs (severe duty), and cars that pass through Yellowstone and Grand Teton National Parks? Close to 3 million people visited Yellowstone Park in 2006 — so how many vehicles was that? Shouldn’t society be looking at their impact on the parks too?

So, what snowmobiles can snowmobile in Yellowstone National Park this winter?

ARCTIC CAT: 2002 4-stroke touring and trail models; 2003 4-stroke touring and trail models; 2004 T660 Touring; 2005 Bearcat W/T; T660; 2006 660 Bearcat W/T; 2006 Panther 660 Touring & Trail models; 2007 Bearcat 660 W/T; Panther 660 Touring & Trail models; 2008 660 Touring; Bearcat 660 W/T; Panther 660 Touring.

POLARIS: 2002 Frontier Touring; 2003 Frontier Classic & Touring models; 2004 Frontier Classic & Touring models; 2005 Frontier Touring; 2006 FS Classic & IQ Touring; 2007 FS IQ Touring; 2008 FS IQ Touring.

SKI-DOO: 2003 Legend Sport GT V-1000 equipped with BAT upgrade; 2004 Elite SE equipped with BAT upgrade; 2005 Legend Sport equipped with BAT upgrade; 2007 Legend Trail, Legend Touring, Expedition Sport V800, Skandic Tundra V800.

YAMAHA: 2006 Yamaha RS Venture Touring with BAT kit; 2007 Yamaha RS Venture and RS Vector, equipped with BAT kit; 2008 Yamaha RS Venture and RS Vector, equipped with BAT kit.

Happy trails!